Neutron Absorbing Component With Gradient Intermediate Layer

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Solution Overview

Problem

Neutron absorbing components in fission reactors face degradation due to chemical reactions with aggressive substances at high temperatures and pressures, leading to reduced functionality and contamination of the reactor environment, necessitating frequent replacements and shutdowns, which result in energy losses and costs.

Innovation Solution

A neutron absorbing component with a core of high neutron absorption material and a protective layer of lower absorption material, featuring a material gradient intermediate layer that provides strong adhesion and reduces stress, ensuring the core is protected from the surrounding environment and preventing contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a neutron absorbing core is used to control reactor reactivity, then the neutron absorption capability is improved, but the component is susceptible to chemical reactions with aggressive substances in the reactor environment, leading to degradation and contamination

Engineering Contradiction:
Improveneutron absorption capabilityVSAvoidchemical reactions with aggressive substances
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A protective layer is introduced as an intermediary between the neutron-absorbing core and the aggressive reactor environment. This protective layer acts as a mediator that prevents direct contact between the core material and harmful substances in the coolant/moderator, thereby eliminating chemical reactions while preserving neutron absorption functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The component is designed as a composite structure combining two materials with complementary properties: a neutron-absorbing material (such as boron or gadolinium) for reactivity control and a chemically inert protective material (such as stainless steel or nickel alloy) for environmental resistance. This composite approach allows each material to perform its specialized function without compromise.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If a protective layer is added to shield the core from the environment, then the protection capability is improved, but the structural integrity and adhesion between layers may be compromised due to thermal and elastic differences

Engineering Contradiction:
Improveprotection from outer surroundingVSAvoidadhesion between core and protective layer
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The protective layer is designed with specific material parameters selected to match or complement the core material's thermal expansion coefficient and elastic modulus. By carefully choosing parameters such as thickness, composition, and thermal conductivity of the protective layer, the design accommodates thermal cycling and stress conditions without compromising adhesion or causing delamination.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the core material is exposed to the outer surrounding, then the manufacturing simplicity is improved, but the contamination of the reactor environment and operational shutdowns increase

Engineering Contradiction:
Improvecomponent structure simplicityVSAvoidcontamination of outer surrounding
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The protective layer serves as a permanent barrier that prevents the core material from interacting with and contaminating the reactor environment. This intermediary layer ensures that even during long-term operation, no radioactive or chemically reactive substances are released into the coolant or moderator, eliminating the need for shutdowns for decontamination or component replacement.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The component maintains its neutron absorption functionality and subcritical status, ensuring accurate reactor control and reducing the risk of contamination and energy losses by preventing the core from reacting with the outer environment, thus extending its operational life and reducing maintenance costs.

Implementation Method 1

The intermediate layer has a material gradient, which means that the concentration of the first material and the second material in the intermediate layer is greater than zero. The material gradient involves a concentration change in comparison with the core and in comparison with the layer.

Methodology Applied
Scientific EffectMaterial gradient:

Implementation Method 2

By means of the material gradient, a transition is formed between the first material in the core and the second material in the layer, which provides a strong adhesion between the layer and the core.

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

The first material has a higher neutron absorption capability than the second material

Methodology Applied
Scientific EffectNeutron absorption: Absorption (physical)

Data Source

PatentEP2543044B1A neutron absorbing component and a method for producing of a neutron absorbing component
Publication Date: 2018.08.15 WESTINGHOUSE ELECTRIC SWEDEN AB
  • EP2543044B1 patent drawingFigure 1~8
  • EP2543044B1 patent drawingFigure 2~5
  • EP2543044B1 patent drawingFigure 6~7

AI summary

The invention regards a neutron absorbing component (1) and a method for manufacturing a neutron absorbing component. The neutron absorbing component comprises a core (2) consisting of a first material, a layer (3) consisting of a second material. The layer encloses a least partly the core and is adapted to protect the core from an outer surrounding. The first material has a higher neutron absorption capability than the second material. The neutron absorbing component is manufactured by sintering in such a way that an intermediate layer (4) is formed between the core and the layer. The intermediate layer has a material gradient that comprises a decrease of the concentration of the first material from the core to the layer and an increase of the concentration of the second material from core to the layer.